Pass numeric data to a highcharts chart with laravel

I'm sending a json via javascript and I send them to the laravel driver, all right up there but when I go back to elaborate the graphic in the lower part it shows me some numbers but not the dates and I do not know what I have to do to show me the numbers, here I leave the codes

$("#elaborar_grafica_anual").click(elaborar_grafica_anual);

function elaborar_grafica_anual() {
    var datachart = new Array();
    var desde_anual = $("#desde_anual").val();
    var hasta_anual = $("#hasta_anual").val();
    var token = $("#token").val();

    var json ={
        desde: desde_anual,
        hasta: hasta_anual
    }
    // console.log(json);
    if (desde_anual == '' || hasta_anual == '') {
        swal({
            title:"Las Fechas Deben ser Obligatorias.",
            text:'',
            type:'warning',
            showCancelButton:false,
            confirmButtonClass:'btn-warning',
            confirmButtonText:'Corregir',
        });
    }else{
        $.ajax({
            method:'POST',
            headers: {'X-CSRF-TOKEN': token},
            url:'http://201.236.212.130:82/intranetcercafe/public/admin/report_precebo_anual',
            data:json
        }).done(function (msg) {
            datachart=msg.data;
            if (datachart.length == 0) {
                swal('No hay Resultados','','error');
            }else{
                console.log(msg);

                Highcharts.chart('grafica', {
                    chart: {
                        type: 'column'
                    },
                    title: {
                        text: 'Reportes de la Conversion Ajustada'
                    },
                    xAxis: {
                        type: 'category',
                        labels: {
                            rotation: -45,
                            style: {
                                fontSize: '13px',
                                fontFamily: 'Verdana, sans-serif'
                            }
                        }
                    },
                    yAxis: {
                        min: 0,
                        title: {
                            text: 'Conversion Ajustada Final.'
                        }
                    },
                    legend: {
                        enabled: false
                    },
                    tooltip: {
                        pointFormat: 'Conversion Final: <b>{point.y} </b>'
                    },
                    series: [{
                        name: 'Conversion Ajustada Final',
                        data: datachart
                        ,
                        dataLabels: {
                            enabled: true,
                            rotation: -90,
                            color: '#FFFFFF',
                            align: 'right',
                            format: '{point.y}', // one decimal
                            y: 10, // 10 pixels down from the top
                            style: {
                                fontSize: '13px',
                                fontFamily: 'Verdana, sans-serif'
                            }
                        }
                    }]
                });
            }
        });
    }
}

laravel driver code

public function grafica_anual(Request $request)
{
    if ($request->ajax()) {
        $collection = Precebo::select('año_destete', DB::raw('sum(numero_inicial) as total'))
        ->whereBetween('año_destete',[$request->desde,$request->hasta])
        ->groupBy('año_destete')
        ->orderBy('año_destete','desc')->get();

        $arrayT = [];
        foreach ($collection as $value) {
            $arrayT[] = [$value->año_destete,$value->total];
        }
        // dd($arrayT);
        return response()->json(['status'=>'success','data'=>$arrayT],200);
    }
}